The present invention relates to a damper assembly for controlling the flow of a gas through a duct. More particularly, the invention relates to a type of damper including a plurality of elongated blades extending across the duct and rotatable from a closed position forming a barrier perpendicular to the flow to an open position wherein the blades are parallel to the flow. Such dampers are commonly referred to as louver dampers. A damper of this general type is shown in U.S. Pat. No. 3,525,328.